Base construction having self-levelling capability

ABSTRACT

A table having a base that is capable of conforming to uneven floor surfaces so that the table is stable on such surfaces. The base has two spaced apart leg members that are joined to one another by a pair of torsionally deformable beams so that one of the leg members can twist relative to the other one. The beams are confined to a region adjacent the table top and remote from the floor contacting portions of the legs, so as to avoid restriction of leg room beneath the table. A base for a square or round table formed of two of the abovementioned base units wherein the respective pairs of beams are excised so that they can intersect without interfering with torsional deformation on the beams.

United States Patent Henley et al.

1451 Dec. 24, 1974 BASE CONSTRUCTION HAVING FOREIGN PATENTS OR APPLICATIONS SELF-LEVELLING CAPABILITY 1,537,888 7/1968 France 248/1883 [76] Inventors: James M. Henley, 1620 Escobita,

P310 A110, Callf- 94306; Earl Primary Examiner-Roy D. Frazier Thordsen, 1 30 Fawn -3 POYtOla Assistant Examiner-Darrell Marquette Valley, Callf- 94025 Attorney, Agent, or Firm-Thomas H. Olson [22] Filed: Oct. 10, 1972 [21] Appl. No: 296,265 [57] ABSTRACT A table having a base that 1s capable of conformmg to v uneven floor surfaces so that the table is stable on UeS- Cl. uch urfaces The base has two paced apart leg members that are joined to one another a pair of [58] Fleld of Search 248/1883; 182/183, 182, torsionally d f bl beams so that one f the leg 182/184 members can twist relative to the other one. The beams are confined to a region adjacent the table top References Clted and remote from the floor contacting portions of the UNITED STATES PATENTS legs, so as to avoid restriction of leg room beneath the 2,633,221 3/1953 Roeder 182/184 table- A base for a Square of round table formed of 2,787,087 4/1957 Whitman 248/ 188,3 two of the abovementioned base units wherein the re- 3;O71,204 1/1963 Piltingsrud 182/184 spective pairs of beams are excised so that they can 3,139,950 7/1964 Borman l82/l84 intersect without interfering'with torsional deforma- 3,204,906 9/1965 Henderson 248/1883 tion on the beams I 3,230,005 1/1966 Staples 297/249 3,758,182 9/1973 Barecki et al 248/1881 6 Clalms, l3 Drawmg Figures 74 l 'L L-J E I i 40 -a =====:=:i\

I v o. 22 Q 28 Q "1 25 1 g 29* ll 1 PATENIED UEC24 I974 sum 1 o g FIGB fi l...]

FIG

PATENTEU 050241974 sum 3 g 5 FIG? BASE CONSTRUCTION HAVING SELF-LEVELLING CAPABILITY This invention relates to a base construction for articles of furniture and like structures, and more particularly to a base structure having the capability of con forming to uneven floor surfaces.

Instability of a structure, such as a table, materially impairs the utility of the structure. By way of example, an unstable dining table impairs the enjoyment that diners might otherwise experience. Instability of tables is particularly acute in restaurants or like public eating establishments wherein the furniture is subjected to extraordinary use and abuse. The problem is also acute with respect to floor surfaces formed of tile or the like such as is typical in patios, because such floors are inherently irregular.

The principal object of the present invention is to provide a base for such table or other structure that conforms to minor irregularities in the floor surface so that the structure mounted on the base will be stable irrespective of the unevenness of the floor surface on which it resides. This object is achieved by providing a pair of legs, each one of which is sufficiently wide to afford two spaced apart points of support, and by joining the legs to one another by two horizontally extending beams. The beams are so proportioned that they are capable of flexural deformation so that all four floor contacting points contact the floor notwithstanding irregularities in the floor. I

A feature and advantage of the base construction of the present invention is that the above-mentioned beams can be provided in virtually any length so that the advantages of the present invention can be afforded in virtually any size structure.

A further object of the present invention is to provide a base construction for a table that affords substantially unimpaired leg space under the table. The aforementioned beams, because they afford the sole support between the two opposite legs and because they are limited in vertical extent, render achievement of this object possible. Because the connection between the ends of the beams and the legs is achieved by a rigid gusset plate, a base construction according to the present invention does not require any structural members, other than the legs, adjacent the floor surface on which the base resides.

Another object of the present invention is to provide a base construction of square configuration that can support such structures as a square or round table top surface. This object is achieved by providing two pairs of legs and a pair of beams spanning each pair. The beams intersect but do not contact one another so that the ability of the beams to torsionally flex is not impaired. A further object of the present invention is to provide a base construction in which many of the same parts can be used irrespective of the size of the base constructed to the end that the necessary inventory of parts is substantially minimized.

The foregoing, together with other objects, features and advantages will be more apparent after referring to the following specification and accompanying drawings in which:

FIG. 1 is a side view of one form of base construction according to the present invention incorporated in a table,

FIG. 2 is a right end view of the table construction of FIG. 1;

FIG. 3 is a left end view of the table of FIG. 1 showing that end on an irregular floor surface;

FIG. 4 is a fragmentary detailed view at enlarged scale of a detail of construction of FIG. 3;

FIG. 5 is a prespective view of another form of the present invention shown supporting a square table top;

FIG. 6 is a fragmentary exploded view of a portion of FIG. 5;

FIG. 7 is a plan view showing a base similar to that shown in FIG. 5 supporting a circular table top;

FIG. 8 is a front view of the base of FIG. 5;

FIG. 9 is a side view of the table of FIG. 8;

FIG. 10 is a view identical to FIG. 8 except that the table base is disposed on an irregular floor surface;

FIG. 11 is a side view of FIG. 10;

FIG. 12 is a rear view of the table of FIG. 10; and

FIG. 13 is a left side view of the table of FIG. 10.

Referring more particularly to the drawings, and specifically to FIGS. 1-3, a table according to the present invention includes a pair of substantially identical legs indicated generally at 12 and 14, which are supported in upstanding spaced apart relation by a pair of substantially identical elongate beams 16 and 18. The opposite ends of the beams are fixed to the legs by substantially identical gusset plates 20 and 22. The gusset plates are secured to the respective legs by vertically spaced through-bolts 22 and 24, and the beams are fixed to opposite faces of the gussets by threaded fasteners 26, or the like. Legs 12 and 14 are substantially identical and include a rigid planar upper portion 28 and a lower base portion 29 that is rigidly attached to the upper portion and defines floor contacting surface portions 30 and 32 which are spaced from one another by a distance sufficient to afford lateral support to the legs.

Secured to the upper edge ofupper section 28 of leg 14 is a cross-piece 34 which is fixed to the leg by suitable fasteners such as screws 36; to the top edge of leg v 12 is secured a cross-piece 40,the attachment being achieved by a single pivotconnection 42. As seen in FIG. 4, pivot connection 42 includes a screw or the like 44 that is threaded into the upper edge of leg 12 and which passes through an enlarged hole 46 in crosspiece 40. One or more spacers 48 between the upper edge of leg 12 and the lower surface of cross-piece Space the two members from one another. Such space is typically about Vs inches and is formed by providing three spacers 48 which in one structure designed according to the invention are flat washers having a central opening sufficient to receive screw 44 therethrough. A compressible strip 50 can be disposed in the space between the lower surface of cross-piece 40 and the upper edge of vertical leg12; the strip is resiliently deformable to dampen the movement of cross-piece 40 about pivot joint 42. v

A rigid planar surface forming member 52 is secured to cross-pieces 34 and 40 to define a table top surface and complete the structure shown in FIGS. 1-3. Screws 54 which extend upwardly through the cross-pieces and into planar table top 52 secure the table top to the base. As can be seen in FIG. 4, the lower surface of table top 52 can be excised as at 54 to accommodate the head of screw 44. An obvious alternative is the provision of a flathead screw 44 which is countersunk into the upper surface of cross-piece 40.

FIGS. 2 and 3. The portion of the floor on which leg 14 rests, see FIG. 2, is level, and floor surface contacting portions 30 and 32 of leg 14 support the leg in an upright position. At the opposite end of the table, an irregularity or bump B exists in the floor; portion 32 of leg 12 rests on the bump and floor contacting portion 30 rests at the same level as the other end of the table so that the entire leg 12 is tilted as shown in FIG. 3. Because beams 16 and 18 have an appropriate thickness to width ratio, the beams flex torsionally so that all four surface contacting portions are in contact with the floor. In the embodiment shown in FIGS. l-3, pivotal connection 42 permits table top 52 to remain in a level condition as can be seen in FIG. 3. The mode of operation depicted in FIGS. 1-3 is typical of a table that is approximately four feet long and employs beams 16 and 18 that are made out of /2 inches douglas fir plywood having a width of approximately 6 inches. In longer tables, in which the opposite ends of table top 52 are spaced from one another sufficiently that the entire table top flexes, pivotal connection 42 can be eliminated by mounting cross-piece 40 rigidly to the upper edge of leg 12. In the embodiment of FIGS. l-3, it will irregularities in the floor surface so that all four surface contacting portions of the structure are in supporting contact with the floor. Obviously, the number of spacers 48 employed depends upon the degree of flexibility in beams 16 and 18 and will depend on the amount of irregularity to be compensated for.

At alternate embodiment of the present invention that provides a base structure for a square or round table surface, is shown in FIGS. 5 et seq. The structure includes legs 56 and 58 which are substantially identical in structure and function to legs 12 and 14 described hereinabove. Legs 56 and 58 are joined to one another by a pair of beams 60 which are joined in face to face contact with gusset plates 62 and 64. The latter gusset plates are identical in structureancl function to gusset plates 20 and 22 heretofore described. It will be noted that beams 60 are centrally excised at 66 leaving a web 68 of reduced width which renders the beams 60 more flexible in torsional movement. Additional flexibility is desirable because the distance between legs 56 and 58 is typically less than the distance between legs 12 and 14 on a rectangular table. Excision 66 perfonns the function of permitting another pair of beams to intersect beams 60 as will be explained in more specific detail hereinbelow.

A second pair of legs 70 and 72 is provided, and such legs are maintained in the appropriate vertical spaced apart relation by paired beams 74. Beams 74 are rigidly attached to legs 70 and 72 by gusset plates 76 which are identical in structure and function to gusset plates 62 and 64 and gusset plates 20 and 22. As seen most clearly in FIG. 6, beams 74 are centrally excised at 76 so that a web of reduced width 78 is provided on each beam 74. The cooperation between excisions 66 and 76 in beams 60 and 74, respectively, can be seen most clearly in FIG. 6. When the parts of the structure are moved to an assembled condition, webs 78 and 68 are out of contact with one another and are free to flex independently.

Legs 56 and 58 each include a base portion 80 which is similar in structure and function to base 29 shown in FIG. 3. The base includes spaced apart floor contacting portions 82 and flat surfaces 84 opposite respective floor contacting portions and parallel thereto. Adjacent each flat surface 84 the base defines a vertically extending abutment 86. Attached to each of legs and 72 is a base 88 which at opposite ends is provided with a downwardly facing bearing surface 90 which, as can be seen in FIGS. 5 and 6, rests on surface 84 of base to cooperate therewith to support base 88. Adjacent bearing surface is a vertical abutment 92 which limits the movement of base 88 with respect to base 80.

Base 80 is rigidly connected to leg 56. Base 88, however, is connected to leg 70 by means of a pivotal connection 94 which permits leg 70 to pivot with respect to base 88. The detailed construction of pivot connection 94 is identical to pivot connection 42 described hereinabove and accordingly needs no further detailed description. v

The base structure is completed by a top plate 96 which is analogous in function to that ascribed to crosspieces 34 and 40 in the embodiment of FIG. 1. Top plate 96 is secured to the upper edges of legs 56 annd 58 by pivot connections 97, which pivot connections are identical to pivot connections 42, and the top plate is rigidly secured to the top edges of legs 70 and 72 by suitable means such as threaded fasteners 98 (See FIG. 7). Secured to the upper surface of top plate 96 is either a square table top forming member 99 (FIG. 5) or a circular table top defining member 100 (FIG. 7 The table top is secured to top plate 96 by screws or the like passed through the edge margin of top plate 96 into threaded engagement with the lower surface of the table top.

It is preferable that the number of spaces associated with pivot connection 94 equal the number of spaces associated with pivot connection 97 so that legs 56, 58, 70 and 72 are identical. Thus, the only differencein construction necessary between the adjacent legs is the particular base 80, 88, with which they are provided at their lower edges. V

- Operation of the second embodiment of the present invention can be understood by reference to FIGS. 8-13. In FIGSQS and 9 the table structure is shown on a perfectly flat floor surface. As can be seen in FIG. 8, the space between the upper surface of leg 56 and the lower surface of top plate 96 is equal on opposite sides of pivot joint 97; a similar condition exists on opposite sides of pivot joint 94 with respect to the space between the lower edge of leg 70 and the upper surface of base 88. It will further be noted from FIGS. 8 and 9 that surface 84 of base 80, and surface 90 of base 88 are in parallel face-to-face contact. In this condition, table top 100 is stable, and rigidly supports loads placed thereon.

If the table is moved to a floor surface having an irregularity, exemplified in FIGS. 10 and 11 by a bump B, on contact point is raised with respect to the other three contact points, which are supported on a level floor surface. To expedite correlation among FIGS. 8-13, the respective floor contacting points or comers of the base are identified by reference numerals 102, 104, 106 and 108. \Vith reference to FIG. 10, it will be seen that corner 104 raises because it rests on bump B.

The consequence of this is that pivot joint 97 at the top of leg 56 pivots thereby permitting top plate 96 and table top 100 to remain level while permitting leg 56 and base 80 to conform to the irregularity in the floor. Leg 58 on the opposite end of beam 60 from leg 56 remains in a normal condition because corners 106 and 108 are on a level floor surface; the twisting or angular displacement of leg 56 with respect to leg 58 is possible because beams 60 torsionally flex throughout their length, particularly at webs 68. Base 88 also resides at a tilted position because of the presence of bump B at corner 104. Such tilted condition is not transmitted to leg 70, however, because of the presence of pivot joint 94. Accordingly, top plate 96 and table top 100 are supported at a level position by leg 70. As can be seen in FIGS. 12 and 13 neither leg 58 and its base 80, nor leg 72 and its base 88 are distorted because the floor surface underlying comers 106, 108 and 102 is level. It should be noted in FIGS. and 11 that only a comer of bearing surface 90 is in contact with surface 84. Thus, leg 88 continues to receive support from the end regions of leg 80 notwithstandingthat base 88 is tilted from a level position.

Bump B, referred to above and shown in the drawings, is but one exemplary irregularity for which the base of the present invention can compensate. The base is equally stable when one or more comers 102-108 resides in a depression or when the floor surface is irregularly sloped, as in the case'with concrete floors that are shaped to afford drainage.

Thus, it will be seen that the present invention provides a base construction that'is self-levelling in that it can conform to irregular floor surfaces so that the article that the base supports, in the foregoing examples a table top, remains substantially level and in a stable, immovable condition. It will be obvious that the present invention can be employed in virtually all types of tables, benches, seats, chairs, and many other structures that are used by placement on horizontal floor surfaces. Thus, the necessity for levelling shims and like expedients for stabilizing an article on an uneven floor are avoided. This is particularly advantageous in restaurants wherein tables must be frequently moved, and reside at one time at a level region of the floor, and at some other time, at an uneven region of the floor. Although 'wood has been employed in several bases designed according to the present invention, the specific material used to construct the base is not critical so long as it has sufficient rigidity to perform the functions referred to hereinabove.

Although two embodiments of the invention have been shown and described, it will be obvious that the other adaptations and modifications can be made without departing from the true spirit and scope of the invention.

What is claimed is:

l. A base for supporting a structure on a generally horizontal floor surface comprising first and second spaced apart rigid planar legs, said legs each having an upper edge and two laterally spaced floor surface contacting portions opposite said upper edge, first and sec- 0nd elongate beams spanning the space between said legs, means for rigidly fixing the longitudinal ends of said beams to said legs adjacent said upper edge so that said legs are supported in parallel spaced apart relation and so that substantial medial portions of the beams intermediate said longitudinal ends are unrestricted portions, said beams being parallelly spaced apart, said beams having a thickness to width ratio such that said unrestricted portions of said beams are flexually deformable in torsion with respect to the longitudinal axes thereof, so that said floor surface contacting portions can yield to conform to uneven floor surfaces, the width dimension of said beams being substantially vertical, and means for attaching said structure to said upper edges of said first and second legs.

2. An article of furniture comprising first and second rigid planar legs, at least one elongate beam, said beam being rigidly secured at its ends to said legs to support said legs in parallel spaced apart relation so that there is an unrestricted portion intermediate the ends, said beam having a thickness to width ratio such that said unrestricted portion of said beam is flexurally deformable in torsion with respect to the longitudinal axis thereof, the width dimension being substantially vertical, means forming a rigid planar surface, and means for attaching said surface forming means to said legs, said attaching means being adapted to avoid interference with the flexural movement of said beam so that said rigid legs can conform to uneven floor surfaces.

3. An article of furniture according to claim 2 wherein said attaching means comprises means for immovably fixing said rigid surface forming means to said first leg and means for fixing said rigid surface forming means to said second leg for pivotal movement relative thereto.

4. A base for supporting a structure on a generally horizontal floor surface including first and second units, said first unit comprising first and second spaced apart rigid planar legs, said legs each having an upper edge and two laterally spaced floor surface contacting portions opposite said upper edge, first and second elongate beams spanning the space between said legs, means for rigidly'fixing the longitudinal ends of said beams to said legs adjacent said upper edge so that said legs are supported in parallel spaced apart relation, said beams being parallelly spaced apart and having a thickness to width ratio such that said beams are capable of flexural deformation in torsion with respect to the longitudinal axes thereof, so that said floor surface contacting portions can yield to conform to uneven floor surfaces, the width dimension of said beams being substantially vertical, and means for attaching said structure to said upper edges of said first and second legs; said second unit comprising third and fourth rigid planar legs, said third and fourth legs each having an upper edge and two laterally spaced bearing members opposite said edge, said bearing members cooperating with said floor contacting portions of said first and second legs for slidable and pivotal movement relative thereto, third and fourth elongate beams and means for rigidly fixing the longitudinal ends of said third and fourth beams to said third and fourth legs so that said third and fourth legs are supported in parallel spaced apart relation, said third and fourth beams being fixed in parallel spaced apart relation and having a thickness to width ratio such that said beams are capable of flexural deformation and torsion with respect to the longitudinal axes thereof; said first, second, third andfourth beams being centrally excised so that said first and second beams intersect said third and fourth beams in noncontacting relation.

5. A base according to claim 4 including means forming a pivotal connection between said third and fourth ends thereof, said first and second legs having upward facing flat surfaces opposite said floor surface contacting portions for supporting said flat surfaces of said body, there being vertical abutments adjacent last said flat surfaces for limiting rotative movement of said bearing members relative said third and fourth legs.

Notice of Adverse Decision in Interference In Interference N 0. 99,056, involving Patent No. 3,855,947, J. M. Henley and E. C. Thordsen, BASE CONSTRUCTION HAVING SELF-LEVEL- LING CAPABILITY, final judgment adverse to the patentees Was rendered Mar. 28, 1977, as to claims 1, 2 and 3.

[Ofiez'al Gazette September 20, 1977.] 

1. A base for supporting a structure on a generally horizontal floor surface comprising first and second spaced apart rigid planar legs, said legs each having an upper edge and two laterally spaced floor surface contacting portions opposite said upper edge, first and second elongate beams spanning the space between said legs, means for rigidly fixing the longitudinal ends of said beams to said legs adjacent said upper edge so that said legs are supported in parallel spaced apart relation and so that substantial medial portions of the beams intermediate said longitudinal ends are unrestricted portions, said beams being parallelly spaced apart, said beams having a thickness to width ratio such that said unrestricted portions of said beams are flexually deformable in torsion with respect to the longitudinal axes thereof, so that said floor surface contacting portions can yield to conform to uneven floor surfaces, the width dimension of said beams being substantially vertical, and means for attaching said structure to said upper edges of said first and second legs.
 2. An article of furniture comprising first and second rigid planar legs, at least one elongate beam, said beam being rigidly secured at its ends to said legs to support said legs in parallel spaced apart relation so that there is an unrestricted portion intermediate the ends, said beam having a thickness to width ratio such that said unrestricted portion of said beam is flexurally deformable in torsion with respect to the longitudinal axis thereof, the width dimension being substantially vertical, means forming a rigid planar surface, and means for attaching said surface forming means to said legs, said attaching means being adapted to avoid interference with the flexural movement of said beam so that said rigid legs can conform to uneven floor surfaces.
 3. An article of furniture accoRding to claim 2 wherein said attaching means comprises means for immovably fixing said rigid surface forming means to said first leg and means for fixing said rigid surface forming means to said second leg for pivotal movement relative thereto.
 4. A base for supporting a structure on a generally horizontal floor surface including first and second units, said first unit comprising first and second spaced apart rigid planar legs, said legs each having an upper edge and two laterally spaced floor surface contacting portions opposite said upper edge, first and second elongate beams spanning the space between said legs, means for rigidly fixing the longitudinal ends of said beams to said legs adjacent said upper edge so that said legs are supported in parallel spaced apart relation, said beams being parallelly spaced apart and having a thickness to width ratio such that said beams are capable of flexural deformation in torsion with respect to the longitudinal axes thereof, so that said floor surface contacting portions can yield to conform to uneven floor surfaces, the width dimension of said beams being substantially vertical, and means for attaching said structure to said upper edges of said first and second legs; said second unit comprising third and fourth rigid planar legs, said third and fourth legs each having an upper edge and two laterally spaced bearing members opposite said edge, said bearing members cooperating with said floor contacting portions of said first and second legs for slidable and pivotal movement relative thereto, third and fourth elongate beams and means for rigidly fixing the longitudinal ends of said third and fourth beams to said third and fourth legs so that said third and fourth legs are supported in parallel spaced apart relation, said third and fourth beams being fixed in parallel spaced apart relation and having a thickness to width ratio such that said beams are capable of flexural deformation and torsion with respect to the longitudinal axes thereof; said first, second, third and fourth beams being centrally excised so that said first and second beams intersect said third and fourth beams in noncontacting relation.
 5. A base according to claim 4 including means forming a pivotal connection between said third and fourth legs and respective said bearing members, and wherein said structure attaching means includes means joining said structures rigidly to said third and fourth legs and means joining said structure to said first and second legs for pivotal movement relative thereto.
 6. A base according to claim 5 wherein said bearing members each comprise a rigid horizontally elongate body having downward facing flat surfaces at opposite ends thereof, said first and second legs having upward facing flat surfaces opposite said floor surface contacting portions for supporting said flat surfaces of said body, there being vertical abutments adjacent last said flat surfaces for limiting rotative movement of said bearing members relative said third and fourth legs. 